The present invention relates to a dual cleaning and sanitizing system useful in icemaking machines which allows deliming and sanitizing simultaneously.
Automatic ice makers run essentially continuously using two basic systems. These systems are the coolant/recycle refrigerant system and the water/ice system. The water/ice system of ice making machines typically includes a water supply, a water reservoir or sump, drain valves from the sump to a line draining to the drain or sewer, a water circulation mechanism, a water distribution means, and appropriate connecting lines. Water is distributed across an ice forming mold, or evaporator plate, and ice is formed thereon. The water which is not frozen flows down the plate into a water container and is returned to the water sump. The ice formed as required is harvested and falls into the ice bin.
Circulating water can lead to the build up of certain deposits on metal surfaces in the water/ice system. In particular, build-up of water hardness chemicals, such as magnesium and calcium salt, can impede water flow and thus the operation of ice making machines, particularly ice making machines running automatically for extended periods of time.
Particularly prone to build up of these deposits are the surfaces of the water sump, the internal surfaces of connecting lines from the sump to the circulating pump and through the circulating pump to the distributor, the distributor itself, and particularly the evaporator plate or ice molding surfaces or fins designed in the ice-forming trays made a part of the evaporator plate and in close proximity or attached directly to the evaporator external surfaces.
Water hardness chemicals have more of a tendency to build up on certain surfaces such as in the water sump where the solenoid drain valve may be activated to drain water periodically. Water containing these or other undissolved salts has a tendency to freeze at lower temperatures than pure water. Water containing higher levels of salts may form what is known in the art as xe2x80x9cwhite ice.xe2x80x9d White ice not only looks bad, it may also taste bad as well. Fresh water which inhibits the formation of xe2x80x9cwhite icexe2x80x9d can be recharged to the water/ice system.
Accumulation of other deposits in addition to water hardness chemicals is also of concern during extended use of automatic ice machines including accumulation of soils, dirts, dusts, and formation and accumulation of various biological deposits such yeasts, algae, molds, fungi, slimes, and other microbiological growths. Such fouling problems in the water-ice system can decrease efficiency and require down-time for maintenance and cleaning.
The formation and build up of such deposits not only impedes the flow of water, but it may result in increased corrosion of metal surfaces, inhibit heat transfer efficiencies particularly on the evaporator plates and ice forming molds, and generally cause poor operation of the ice maker. Thus, periodic cleaning and sanitizing of the water-ice system surfaces in order to maintain proper ice making operations.
Cleaning processes typically involved dismantling the portions of the ice making machine containing the soiled surfaces and washing and scrubbing the surfaces using acidic cleaner compositions. Use of acidic cleaners further required careful and extensive rinsing of the surfaces to avoid contact with ice later formed. Once the cleaning/rinsing was complete, then the machine must be reassembled to its usable state. The cleaning process is therefore labor intensive, costly and inefficient.
U.S. Pat. No. 5,289,691 describes a self-cleaning self-sterilizing ice making machine that has a coolant/refrigerant system, a water-ice system, a cleaning/sterilizing system and a microprocessor operated control system interconnecting the above systems.
The present invention relates to an improved, novel cleaning and sanitizing system in which both cleaning, i.e. deliming, and sanitizing can occur substantially simultaneously using a single system.
The dual liquid deliming and sanitizing system of the present invention may be employed for cleaning and sanitizing any water circulation system which includes a first product container including a liquid cleaning composition, a second product container including a liquid sanitizing composition, a pre-mix reservoir having an exit port which is in fluid communication with the water circulation system and a device in fluid communication with the first container and the second container configured and arranged for transporting liquid from the first and second containers to the pre-mix reservoir. The liquid deliming composition and the liquid sanitizing composition form a mixture in the reservoir. In the case of a reactive system in which a sanitizer is formed, the pre-mix reservoir allows the reaction to proceed a rate fast enough for integration with an automatic cleaning cycle.
In one particular embodiment, the pre-mix reservoir has an exit port which drains into a sump such as in an automatic ice making machine.
More particularly, the present invention relates to a deliming and sanitizing process for an ice machine having a water flow system, a sump and a drain, and having a headspace within the interior accessible to the interior of the machine including the steps of injecting an acidic delimer composition into the sump and injecting a sanitizing composition into the sump. This can be more advantageously accomplished by injecting the delimer composition and the sanitizer composition into a pre-mix reservoir prior to transportation into the sump. From the sump, the mixture then cycles through the water flow system.
In some embodiments, a metal chlorite composition, a metal hypochlorite composition, a quaternary ammonium composition, an acid-anionic composition, a peracetic acid composition is added to an acidic delimer in the system. Ozone generating compositions may also be employed.
In one particular embodiment of the present invention, a metal chlorite composition is added to an acidic delimer composition which forms chlorine dioxide.
The present invention advantageously allows sanitizing and deliming simulataneously in a liquid phase, and in some embodiments also allows for gaseous sanitization of the head space of a chamber or vessel, such as the head space in an ice making machine.
The dual liquid deliming and sanitizing system of the present invention may be integrated with and employed for cleaning and sanitizing any automatic water circulation system. The dual liquid cleaning and sanitizing system is easily integrated with an automatic ice making machine, for example.
For maximum benefit, the device and method of the present invention may be employed in combination with a device as described in commonly assigned copending patent application, attorney docket number E14.2-9970, DEODORIZING AND SANITIZING EMPLOYING A WICKING DEVICE incorporated by reference herein in its entirety.